#include <iostream>
#include <fstream>
using namespace std;

//ifstream::pos_type size;
//char * memblock;
char riff[4], id[5], fmt1[5];
long s, datasize, bitrate;
short compressioncode, chan;
char* filename = "sample2.wav";

char* mute(char* data){
data[0] = 0;
data[1] = 0;
data[2] = 0;
data[3] = 0;
return data;
}

void process (char* data, long datasize, short chan, char* fname, int si) {
//useless test function, mutes data
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
file.seekg (0, ios::beg);
char header[si];
file.read(header,si);
ofstream fileo;
fileo.open("output.wav", ios::out | ios::app | ios::binary);
if (fileo.is_open()) { 
cout << "file opened\n"<<header<<"\n";
fileo.write(header,si);
char piece[8];
int len = chan*4;
for(int i=0; i<datasize/len; i++){
	file.read(piece, len);
	if(chan==2){
		char one[4]={0,0,0,0};
		char two[4]={0,0,0,0};
		for(int k=0;k<4;k++){
		one[k] = piece[k];
		two[k] = piece[k+4];}
		char* one1 = mute(one);
		char* two1 = mute(two);
		fileo.write(one1,4);
		fileo.write(two1,4);
		}
	else{
		char* pie;
		pie = mute(piece);
		fileo.write(pie,4);
		}
	}

fileo.close();
}
file.close();
}
}

void insert (char* fname, int si, char* data, int datasize, string text) {
//this method inserts the message into the file header
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
//cout << si << "\n";
file.seekg (0, ios::beg);
char beg[16];
file.read(beg,16);
long size;
file.read((char*)&size,4);
//cout << size << "\n";
char rest[si-28];
file.read(rest,si-28);
char dat[8];
file.read(dat,8);
int str = text.length();
size+=str;
ofstream fileo;
fileo.open("output2.wav", ios::out | ios::binary);
if (fileo.is_open()) { 
	fileo.write(beg,16);
	//cout << "size is " << size << "\n";
	fileo.write((char*)&size,4);
	fileo.write(rest,si-28);
	char tex[str];
	for(int i=0; i<str; i++){
	tex[i] = text[i];}
	fileo.write(tex,str);
	fileo.write(dat,8);
	fileo.write(data,datasize);
	}
cout << "message written\n";
fileo.close();
}
file.close();
}

void insert2 (char* fname, int si, char* data, int datasize, string text) {
//this method inserts each byte of the message into the least significant bytes of the data chunks
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
//cout << si << "\n";
file.seekg (0, ios::beg);
char beg[16];
file.read(beg,16);
long size;
file.read((char*)&size,4);
//cout << size << "\n";
char rest[si-28];
file.read(rest,si-28);
char datbs[4];
file.read(datbs,4);
long datlen;
file.read((char*)&datlen,4);
int str = text.length();
size+=4; //just 4 extra bytes for length of string
ofstream fileo;
fileo.open("output3.wav", ios::out | ios::binary);
if (fileo.is_open()) { 
	fileo.write(beg,16);
	//cout << "size is " << size << "\n";
	fileo.write((char*)&size,4);
	fileo.write(rest,si-28);
	char tex[str];
	for(int i=0; i<str; i++){
	tex[i] = text[i];}
	fileo.write((char*)&str,4);
	fileo.write(datbs,4);
	fileo.write((char*)&datlen,4);	
	char temp[4];
	int now=0;
	for(int k=0; k<str; k++){
		for(int j=0; j<4; j++){
		temp[j] = data[now];
		if(j==0){
		temp[0]=tex[k];}
		fileo.write((char*)&temp[j],1);
		now++;
		}	
	}
	int textsize=4*str;
	datlen-=textsize;
	datlen = datasize-16-28+si-8-str;
	//cout << "datlen" << datlen;
	for(int g=0; g<datlen; g++){
	fileo.write((char*)&data[g+textsize],1);	
	}
	}
cout << "message written\n";
fileo.close();
}
file.close();
}

void extract (char* fname) {
//this extraction method corresponds to the first insertion method/algorithm (aka file header)
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
//cout << "debug";
file.seekg (0, ios::beg);
char beg[16];
file.read(beg,16);
long size;
file.read((char*)&size,4);
size-=16;
//cout << size << "\n";
char junk[16];
file.read(junk,16);
char te[size];
file.read(te,size);
cout << "Message extracted:\n";
for(int k=0; k<size; k++)
{
	cout << te[k];
}
cout << "\n";
}
file.close();
}

void extract2 (char* fname) {
//this extraction method corresponds to the second insertion method/algorithm (aka least significant bytes)
ifstream file (fname, ios::in|ios::binary);
if (file.is_open())
{
//cout << "debug";
file.seekg (0, ios::beg);
char beg[16];
file.read(beg,16);
long size;
file.read((char*)&size,4);
//long sizcopy = size;
//size-=16;
//cout << size << "\n";
char junk[size-4];
file.read(junk,size-4);
int str;
file.read((char*)&str,4);
char datchunk[8];
file.read(datchunk,8);
string message;
char tem[1];
cout << "Message found:\n";
for(int k=0; k<str; k++){
	for(int j=0; j<4; j++){
		file.read(tem,1);
		if(j==0){
			cout << tem[0];
			}
	}	
}
cout << "\n";
}
file.close();
}

int main (int argc, char *argv[]) {
    char* filename = "test.wav";
    string text;
    if(argc==2){
    filename = argv[1];}
    if(argc==3){
    filename = argv[1];
    if(strcmp(argv[2],"-x")==0){
	extract(filename);
	exit(0);
	}
    else if(strcmp(argv[2],"-x2")==0){
	extract2(filename);
	exit(0);}
	}
    if(argc==4){
    filename = argv[1];
    text = argv[3];
	}
    //cout << filename << " " << text << "\n";
    ifstream file (filename, ios::in|ios::binary); //filesize = 15198 bytes
    if (file.is_open())
    {
    file.seekg (0, ios::beg);
    file.read (riff, 4);
    file.read ((char*)&s, 4);
    file.read (id, 4);
    //cout << riff << " " << s << " " << id << "\n";
    if(strcmp(riff,"RIFF")==0) //correct file type
	{ //cout << "file type is RIFF\n";
	if (strcmp(id,"WAVE")==0) //is a wav file
		{ //cout << "file is a WAV\n";
		//cout<<"filesize is "<<s<<" bytes\n";
		file.read (fmt1, 4);
		if(strcmp(fmt1, "fmt ")==0){
		long si;
		file.read ((char*)&si, 4);
		file.read((char*)&compressioncode, 2);
		//cout << "compression code is " << compressioncode << "\n";
		file.read((char*)&chan, 2);
		//cout << "num of channels " << chan << "\n";
		if(chan==1){
		cout << "mono" << "\n";}
		else if(chan==2){cout << "stereo" << "\n";}
		else cout << "other" << "\n";
		file.read((char*)&bitrate, 4);		
		cout << "sample bit rate " << bitrate << "\n";
		char details[si-8];
		file.read(details,si-8);
		char datatag[4];
		file.read(datatag,4); 
		int newsize;
		while(datatag[0]!='d'){
		file.read((char*)&newsize,4);
		//cout << newsize << "\n";
		char temp[newsize];
		file.read(temp,newsize);
		file.read((char*)&datatag,4);
		//cout << datatag << "\n";
		}
		cout << "data chunk reached" << "\n"; // if datatag = "data", we have reached data chunk
		file.read((char*)&datasize,4);
		//cout << datasize << "\n";
		cout << "datasize: " << datasize << "\n";
		char data[datasize];
		char piece[8];
		file.read(data,datasize);
		file.close();
		int siz = si+28;
		cout << "data read successfully\n";
		if(argc==2){
		process(data, datasize, chan, filename, siz);}
		else if(argc==4&&strcmp(argv[2],"-i")==0){
		insert(filename, siz, (char*)&data, datasize, text);}
		else if(argc==4&&strcmp(argv[2],"-i2")==0){
		insert2(filename, siz, (char*)&data, datasize, text);}
		}
		}
		}
		

	

    else{file.close();}

    //cout << "the complete file content is in memory\n";

   // delete[] riff, s, id, fmt1, chan;
  }
  else cout << "Unable to open file";
  return 0;
}